The communications field is mainly related to time division duplex (TDD), frequency division duplex (FDD), and co-time co-frequency full duplex (CCFD).
In a current CCFD solution, CCFD is implemented only on a CMTS side, and on a CM side, all CMs may be grouped based on an interference relationship (also referred to as isolation) between the CMs. Specifically, CMs that interfere with each other or have mutual interference that does not meet a requirement are grouped into a group to implement FDD within a CM group, and CMs that do not interfere with each other or have mutual interference that meets a requirement are grouped into different groups. CCFD is implemented between groups to improve spectral efficiency.
It may be learned from the foregoing that CM grouping is mainly implemented based on an interference relationship between CMs. In other words, the interference relationship between CMs can determine CM grouping. How to obtain an accurate interference relationship between CMs is always an issue studied in the industry.